A miniature relay has a plurality of prongs two of which are connected to the relay coil and the others of which are connected to the various relay contacts and poles. Such a relay is typically secured to a printed-circuit board by a mount formed as a dielectric body having on one side an array of seats in which the prongs can fit, and provided in each seat with a socket for the respective prong. Conductors extending from the sockets are in turn usually formed as pins that can fit into respective holes in the circuit board, for soldering to respective printed conductors on its opposite face. The relay can therefore be plugged into the mount after same has been soldered in place on the board, making the relay replaceable and protecting it from the heat of the soldering operation.
Such an arrangement is usually unusable for a relay of the miniature type nowadays capable of carrying relatively high current and normally connected to high-amp wires. The leakage paths and air gaps are insufficient for currents of, say, 16A. Even when particularly wide printed conductors terminating at special connectors for the high-amp wires are used, the arrangements do not usually meet strict safety standards. Double laminated boards that space the conductors as much as possible have not been found to give much added safety.